IAQ Glossary/FAQ's

Glossary of Related Terms

Indoor Air Quality	IAQ is a term used to describe the characteristics of the indoor climate of the building, with special concern for the impact on occupant health. In the beginning this meant temperature, humidity, exchange air (air from outside) and dust levels. The number of important parameters of interest has dramatically expanded in recent years as new technologies have come on stream.
Air Passages	Openings through or within walls, through floors and ceilings, and around chimney flues and plumbing chases, that permit air to move out of the conditioned spaces of the building.
Animal Danger	Tiny scales of animal skin.
Allergen	A substance capable of causing an allergic reaction because of an individual's sensitivity to that substance.
Allergic Rhinitis	Inflammation of the mucous membranes in the nose that is caused by an allergic reaction.
Atopy	A peculiar form of allergy marked by a familial tendency to certain hypersensitivities, as hay fever, asthma, atopic dermatitis.
Biological Contaminants	Agents derived from, or that are, living organisms (e.g., viruses, bacteria, fungi, and mammal and bird antigens) that can be inhaled and can cause many types of health effects including allergic reactions, respiratory disorders, hypersensitivity diseases, and infectious diseases.
Breathing Zone	Area of a room in which occupants breathe as they stand, sit, or lie down.
Building Envelope	Elements of the building, including all external building materials, windows, and walls, that enclose the internal space.
Building-Related Illness (BRI)	Diagnosable illness whose symptoms can be identified and whose cause can be directly attributed to airborne building pollutants (e.g., Legionnaire's disease, hypersensitivity pneumonitis). Also: A discrete, identifiable disease or illness that can be traced to a specific pollutant or source within a building. (Contrast with "Sick building syndrome").
Chemical Sensitization	Evidence suggests that some people may develop health problems characterized by effects such as dizziness, eye and throat irritation, chest tightness, and nasal congestion that appear whenever they are exposed to certain chemicals. People may react to even trace amounts of chemicals to which they have become "sensitized."
Conditioned Air	Air that has been heated, cooled, humidified, or dehumidified to maintain an interior space within the "comfort zone." (Sometimes referred to as "tempered" air.)
Drain Tile Loop	A continuous length of drain tile or perforated pipe extending around all or part of the internal or external perimeter of a basement or crawlspace footing.
Drain Trap	A dip in the drain pipe of sinks, toilets, floor drains, etc., which is designed to stay filled with water, thereby preventing sewer gases from escaping into the room.
Environmental Agents	Conditions other than indoor air contaminants that cause stress, comfort, and/or health problems (e.g., humidity extremes, drafts, lack of air circulation, noise, and over-crowding).
Fungi	Any of a group of parasitic lower plants that lack chlorophyll, including molds and mildews
Hepa	High efficiency particulate arrestance (filters).
Humidifier Fever	A respiratory illness caused by exposure to toxins from microorganisms found in wet or moist areas in humidifiers and air conditioners. Also called air conditioner or ventilation fever.
HVAC	Heating, ventilation, and air-conditioning system.
Hypersensitivity	The state of being abnormally sensitive or susceptible, as to the action of allergens.
Hypersensitivity Diseases	Diseases characterized by allergic responses to pollutants. The hypersensitivity diseases most clearly associated with indoor air quality are asthma, rhinitis, and hypersensitivity pneumonitis. Hypersensitivity pneumonitis is a rare but serious disease that involves progressive lung damage as long as there is exposure to the causative agent.
Hypersensitivity Pneumonitis	A group of respiratory diseases that cause inflammation of the lung (specifically granulomatous cells). Most forms of hypersensitivity pneumonitis are caused by the inhalation of organic dusts, including molds.
Indicator Compounds	Chemical compounds, such as carbon dioxide, whose presence at certain concentrations may be used to estimate certain building conditions (e.g., airflow, presence of sources).
Indoor Air Pollutant	Particles and dust, fibers, mists, bioaerosols, and gases or vapors.
MCS	See "Multiple Chemical Sensitivity."
Microbiologicals	See "Biological Contaminants."
Multiple Chemical Sensitivity (MCS)	A condition in which a person reports sensitivity or intolerance (as distinct from "allergic") to a number of chemicals and other irritants at very low concentrations. There are different views among medical professionals about the existence, causes, diagnosis, and treatment of this condition.
Organic Compounds	Chemicals that contain carbon. Volatile organic compounds vaporize at room temperature and pressure. They are found in many indoor sources, including many common household products and building materials.
PELs	Permissible Exposure Limits (standards set by the Occupational, Safety and Health Administration - OSHA).
Pollutant Pathways	Avenues for distribution of pollutants in a building. HVAC systems are the primary pathways in most buildings; however all building components interact to affect how air movement distributes pollutants.
Psychogenic Illness	This syndrome has been defined as a group of symptoms that develop in an individual (or a group of individuals in the same indoor environment) who are under some type of physical or emotional stress. This does not mean that individuals have a psychiatric disorder or that they are imagining symptoms.
Psychosocial Factors	Psychological, organizational, and personal stressors that could produce symptoms similar to those caused by poor indoor air quality.
Sick Building Syndrome (SBS)	Term that refers to a set of symptoms that affect some number of building occupants during the time they spend in the building and diminish or go away during periods when they leave the building. Cannot be traced to specific pollutants or sources within the building. (Contrast with "Building related illness").
Soil Gas	The gas present in soil which may contain radon.
Sources	Sources of indoor air pollutants. Indoor air pollutants can originate within the building or be drawn in from outdoors. Common sources include people, room furnishings such as carpeting, photocopiers, art supplies, etc.
TVOCs	Total volatile organic compounds. See "Volatile Organic Compounds (VOCs)"
Volatile Organic Compounds (VOCs)	Compounds that vaporize (become a gas) at room temperature. Common sources which may emit VOCs into indoor air include housekeeping and maintenance products, and building and furnishing materials. In sufficient quantities, VOCs can cause eye, nose, and throat irritations, headaches, dizziness, visual disorders, memory impairment; some are known to cause cancer in animals; some are suspected of causing, or are known to cause, cancer in humans. At present, not much is known about what health effects occur at the levels of VOCs typically found in public and commercial buildings.

IAQ Glossary/Frequent Questions

IAQ Glossary/FAQ's

Glossary of Related Terms

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